CVE-2026-90209

Name	CVE-2026-90209
Description	In the Linux kernel, the following vulnerability has been resolved: s390/debug: Fix deadlock during unregister Unregistering an s390dbf debug area while one of the associated debugfs files is being written to can cause a deadlock: $ echo >.../vmur/level $ rmmod vmur =================================================== debugfs write debugfs_file_get() debug_unregister() mutex_lock(debug_mutex) debugfs_remove() wait for debugfs_file_put() debug_file_ops.write() debug_input() mutex_lock(debug_mutex) ==> DEADLOCK Fix this by splitting debug_unregister() into an s390dbf and debugfs part, and running only the s390dbf part with debug_mutex locked.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DSA-6528-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
linux (PTS)	bookworm	6.1.176-1	vulnerable
	bookworm (security)	6.1.187-1	vulnerable
	trixie	6.12.107-1	vulnerable
	trixie (security)	6.12.111-1	fixed
	forky	7.2.8-1	fixed
	sid	7.2.9-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
linux	source	trixie	6.12.111-1		DSA-6528-1
linux	source	(unstable)	7.2.6-1

https://git.kernel.org/linus/445c31ac638fd1af203d79bdf25fc0cb3149fbbc (7.3-rc1)